Modified alkyd resins from an alkyd resin and an alkoxy hydrocarbon silane



Patented July 29, 1952 V I 1. This invention relates to'improved alkydresins, to a method for the preparation thereof, and, to coatingcompositions'containing the same. 3 M Alkyd resins are widely usedincoating compo} sitions, and in general produce, a tough; durable filmhaving a satisfactory lustre. However,jalkyd resin' coating compositionsexhibit'low resistance to the actions pf water and alkalies;Furthermore, coating compositions containing alkyd resins which aremodified with 'non drying' oils generally do not hardensuflicientl'y'even on prolonged baking at high temperaturesi'- It istherefore an object ofthis'invention to 7 Application Mayra,- i947, I 1l l o i u "5 "v accl im; 401'; 260-22) provide an alkyd resin which whenused in a 3 coating composition dries to yield a film of increasedresistance'to alkalies and water.

,It'is also an object or thisinvention to'prod'uce alkyd resins whichwhen incorporated into coat ing compositions dry at an increased rate topro l duce a film of increased hardness and flexibility. ,It is afurther object'of this invention to pre pare alkyd resins which whenincorporated I into coating compositions have satisfactory lcol'orstability when baked. v

The aforementioned andfotherobjeots are accomplished in accordance withthis invention by incorporating into an alkyd resin an organosiliconcompound having the "generic formula RySiXn in which R is an alkyl,alkenyl or aryl ""An alkyd resin was prepared by "reacting39 partsof'soy bean 1fatty acids,f40;.3 fparts of ph-thalic anhydride and28;3Fpartjsfof glycerol,

"thefreaction being efiected' hy'heating the foregoing materials undera'carbon1dioxide blanket to a temperature of 420 untilfan acid'numb'er 7of 5-1'0'was'obtained." The'viscos'ity'ofthefinished alkyd resin was inthe range 'of. Y3-,-Z5 (Gardner -I-Ioldt viscosimeter) when dissolved invkylol to form a solution having a 60% solids "content,"

Monoamyl triethoxysilane wasmixed with the 60% solids solution of thealkyd resin in xylol in,

1:1 and 1:3 proportion-on thesolids basis. -The twomixtures and theunmodified alkyd resin by itself were reduced to a 50% solids solutionin xylol, were applied to a panel, and ,were then baked at 5300"; F. fortwo hoursr The followin table indicates the 'Sward Rocker hardnesses andthe resistances of the baked films to 2% aqueous causticrsoda. l; V 1

% Spy Alkyd 25% monoamyl triethoxysilone 50% Soy Alkyd 50% monoamyl'triethoxysilane Soybean Alkyd Sward Rocker lilardness After Baking at300 F its 1 Complete breakdown afterl5 minutes. I 'l' S -Indicatessoftening.

1 This number indi ates time in hours of immersion in the caustic zExample II V An alkyd resin was prepared by reacting, 29.7 parts ofcoconut fatty. acids,.47.5 parts of phthalic ,anhydride and31.-8 partsof glycer.ol,.,the reaction being .efiecte'd by heating the ingredientsunder an inert. atmosphere to 380 and holding them at thattemperature-until the acid number ofthe mixture had dropped to 4-8. Theviscosity of the. finished resin was about P-U (Gardner-Holdtviseosimeter) at 50% solids in'xylol.

:l;8. 2.; gins. of monoallyl itriethoxysilane was placed ina flask with200 gms. of ;a 50% solution of thealkyd resin in xylol.- The flask was;fitted with a stirrer, a small fractionating column, a reflux head and acondenser, and the mixture was heated thereinuntil the temperature ofthemixture reached C. The temperature at the top of thereflux column was78 (7., and ethyl alcohol was removed by distillation'until -about; 4,lems.

thereof was collected. Thisamount of ethylal} v cohol corresponded tothe reaction of 'oneethoXy group onthe monoallyl triethoxysilane withthe .hydroxy groups of the alkyd resin. The solution remaining in theflask had a Gardner-Holdt viscosity of about T at asolids content ofabout '57 in-xyloh A0005 in. film was applied to a'steel panel, andbaked at 392 F. for hour. The

filr'n'f cured, rapidly to every hard and flexible coating havingexcellent adhesion to the panel.

' A pigmented film was preparedffrom a paint containing 45% of titaniumdioxide, 24.7% ofthe modified alkyd resin, and 30.3% of xylol. The filmwas baked at 400 F. for. hour to yield a coating having a Sward'Rocker'hardness of 15. After a one hour test with 3% "aqueous sodium hydroxide'"solution,"the film laid" down by the Example III 200 gms. of a 50%solution in xylol of the alkyd resin repare -as described underthe firstparagraph ofiEizample II and 27.3 gms. ofdiisopropyl diethoxysilane wererefluxed at 140 C. for one hour. 8 gms. of ethyl alcohol was distilledoff,

and the viscosity of the solution remainingin the flask was Y(Gardner-Holdt v sqes meteag, .Wh'n

the solution was applied to a panel, the filth resulting therefrom had aSward Rocker hardness of 15 after baking for one hour at 177 C; ""Thefilm softened in 3% aqueous caustic soda after,

1 hours, whereas a corresponding film of the unmodified alkyd suffered acomplete break-down in 10 minutes.

The foregoing examples illustrate the method of "the present inventionfor the preparation of improved alkyd resins by reacting them"withcertain organosilicon compounds. The reaction between the alkyd resinand the silane'may be effected over a wide range of temperaturese. g],by refluxing them at low temperatures when dissolvedi-n an inert organicsolvent, or by baking the alkyd resin and the s'ilane in contact witheach other at temperatures below the boiling point of the organosilaneused for about minute's and then at temperatures which are customarilyemployed in the art of baking alkyd resins which have not been somodified. A wide range of relative proportions of silane to alkyd resinmay be employed. Thus, the ratio of the number of molecules of thesilane to the sum of, the numbers of the hydroxy andcarboxy groups ofthe alkyd resin should be from about 0.05 to about 1.0.

Thebeneficial effects of the present invention may be obtained byreacting one of: the specified silaneaor mixtures thereof, with. any ofthe wide variety of 'alkyd resins kn'ownin thearth .Henee,

place of the particular alkydri'esi-ns which'were modified in theexam'plesthere maybe similarly modified alkyd resins prepared in knownman-f n'r'by the reaction of polycarboxylic acids (e. g, phthalic acid,p'hthalic'anhy'drider malcic' acid,

maleic ail-hydride, funlall'o acid, OXalic acid, Silo; Ciliic' fluid,glutaric acid, adipic acid, pim'li e" acid, sbacic acid,- iso'fihthalic"acid, terephthaue acid, etc; with polyhydroxy alcohols(e.-g;,-glycer'dl; pentaerythritol, trimethylene glycol-,- propylene"glycol, diethylene glycol; erythritol, mannitoLsorbitol; etc); In thexamples, the alkyd re's'ins' described were modified withmonoca-rboxylic acids derived from fatty -oil's',; butthe advantages ofthe pr se t i vention may "be realized regardless; or.

si lan, employed in the 'examp1es,im'ere may be subs'titutedany silanehavingtlie generic formula ployed as modifiers.

4 RtSiXl-y, in which R is an alkyl, alkenyl or aryl radical, X is analkoxy radical, and y is one, two or three. Thus, R may be the methyl,ethyl, npropyl, i-propyl, n-butyl, n-amyl, i-propenyl, allyl, 2-butenyl,isobutenyl, methallyl, phenyl, benzyl, phenylethyl, o-methylphenyl,m-methylphenyl, p-methylphenyl, 3,5-dimethyl phenyl, etc. radicalFurthermore, the silane-may be of the mixed variety, andmixtujres'ofsilanes having the aforementioned generic formula may alsobe em- The alkoxy radical X may suitably be the methoxy, n-propoxy,ipropoxy,

'ri butox-y', etc radical as well as the ethoxy radicaisriown in theexamples.

As the examples illustrate, the present invention also comprehendscoating compositions containing the silane-modified alkyd resinsprepared as hereinbefore described, such coating compositi on beingsolutions of the silane-modified alkyd resins. in any wide variety ofsolvents which are customarily employed in the art for coatingcompositions, such as benzene, toluene, the xylenes, mineral spirits,turpentine, etc." In addition, such coating compositions inaycontainpigments, such as titanium dioxide, lithopoii, zinc oXideetc'f, and/ordriers such as cobalt and manganese nafihtlienates and creates; 1

"This application isa commusuemn-part;or mycopendirig applicatiomseriaiNo. 461,892, filed October 13, 1942. entitled Artificial Structures aridCoiiipo'sitionsfor Producing the Same, and now abandoned. li'claim; Y II 1 A modified alkyl r' produced jbi reac'tn an alkyl resin withacompound of th gerierio formula RySiXi-gj, which'R s a 'subsutuemselectedfrom t'hegroup consisting alkenyl radi cals having from threetofour carbon atonis;.alkyl and aryl radicals, X alko'ii'y radicalthavinfrom one-to five carbon atoms, andy is an integer ii in one to three,eta-tem erature sufficient-.1120 remoye alcohol formed by the reaction.

2-; The product defined by'ciaim" 1 in which the alkyd resin isgly'cerol' phth'allic .anhyd'r'i'de resin.

3. The productdefined am 2 in which the ,glycrohphthallic anhydrid'eresin is" modified witlia drying oil. A y

The product as defined by claim I in which 1.5. ,f I'h'e product definedby claim 1 in which 17' is '2. V i I 6. Theproduct defined by claim 1 inwhich Elli S 31 1" V which comprises reacting an alkyd resin with acompound of the generic formula R Si'Xot'in which R is asubstituentsel''oted from the group consisting of alkenyl radicalshaving: from three to four c rbon atoms, alk'yl and aryl radicalaX isanalkoxy radical having from one to five carbonat'oms. and t: isaninteger from one to th'fefaat atemperature at which alcohol'form'edbyfthe' reaction is 'drivenoff. I, j

18. The method .of claim 7 in which the alkyd resin is a g'l'ycerolplithallic anhydrideresin.

' aij'rue methoaere aimswhich-the gl cerolp'h'thallic anhydr'ide resinis modified with a dry"- 10-. The method'of claim 'l in which y is 1-.1:1. The metnod rc a imn; whichy is 2. 12. The method ofclainr'Tirrwhicli y is 3.

' FRANK J. 'sOWA.

(Reference-s" on renown-1g sage) The following references are of recordin the REFERENCES CITED file of this patent:

UNITED STATES PATENTS Number MacKenzie et al. Mar. 14, 1950 6 FOREIGNPATENTS Number Country Date 583,754 Great Britain Dec. 80, 1946 OTHERREFERENCES Rochow, Chemistry of the Silicones, Wiley 1946,"

pages 34 to 36.

Simmonds and Ellis, Handbook of Plastics, D. Van Nostrand Co., 1943,page 963.

General Electric Co., Glyptal Alkyd Resins, CD C-194, 2-51, a folderwith two pages, received April 30, 1951.

Morrell, Synthetic Resins and Allied Plastics, London, 1937, pp. 13 to15 and 212.

Wakeman, The Chemistry of Commercial Plastics, Reinhold, 1947, pp. 216and 217.

1. A MODIFIED ALKYL RESIN PRODUCED BY REACTING AN ALKYL RESIN WITH ACOMPOUND OF THE GENERIC FORMULA RYSIX4-Y, IN WHICH R IS A SUBSTITUENTSELECTED FROM THE GROUP CONSISTING OF ALKENYL RADICALS HAVING FROM THREETO FOUR CARBON ATOMS, ALKYL AND ARYL RADICALS, X IS AN ALKOXY RADICALHAVING FROM ONE TO FIVE CARBON ATOMS, AND Y IS AN INTEGER FROM ONE TOTHREE, AT A TEMPERATURE SUFFICIENT TO REMOVE ALCOHOL FORMED BY THEREACTION.